N-substituted tetrahydroquinolines for use as antioxidants in lubricants

ABSTRACT

Compounds useful as additives for lubricants, hydraulic oils and metal-working fluids include those of formula IV ##STR1## where R 1  and R 2  are independently alkyl or substituted aryl, R 3  and R 13  are independently hydrogen or methyl, R 6  is alkyl, alkenyl, aralkyl or substituted benzyl, and R 15  and R 16  are independently hydrogen, alkyl, aryl or aralkyl.

This is a divisional of application Ser. No. 135,964, filed Dec. 21,1987, now U.S. Pat. No. 4,828,741 issued on May 9, 1989.

The present invention relates to lubricant, hydraulic oil ormetal-working fluid compositions containing as stabilizers N-substituted1,2,3,4-tetrahydroquinolines, to novel N-substituted1,2,3,4-tetrahydroquinolines, and to the use of such N-substituted1,2,3,4-tetrahydroquinolines as stabilizers in lubricants, hydraulicoils and metal-working fluids.

In general, various additives are added to mineral and syntheticlubricants, hydraulic oils or metal-working fluids to improve theirperformance characteristics. In particular there is a demand foradditives which actively inhibit the oxidation or ageing of thelubricant, hydraulic oil or metal-working fluid and thus extend theirlife.

EP-A-No. 72,349 discloses N-unsubstituted 1,2,3,4-tetrahydroquinolinesfor use as antioxidants in lubricants. DE-A-No. 2,156,371 describesN-substituted 1,2,3,4-tetrahydroquinoline derivatives for use asstabilizers in colour former compositions for pressure-sensitiverecordings. Furthermore, 1-amino- or1-hydroxyalkyl-1,2,3,4-tetrahydroquinolines are described in U.S. Pat.No. 3,247,211 as starting materials for dyes. Moreover, U.S. Pat. No.2,846,435 discloses N-alkyl-1,2,3,4-tetrahydroquinolines for use asrubber stabilizers, and GB-A-No. 795,497 discloses N-substituted1,2,3,4-tetrahydroquinolines for use as flexibility improvers forpolymeric polyolefin coatings on metals.

The present invention accordingly provides a composition containing

(a) at least one lubricant, hydraulic oil or metal-working fluid basedon mineral oil or synthetic oils and

(b) 0.05-5% by weight, based on the total weight of the lubricant,hydraulic oil or metal-working fluid composition, of at least onecompound of the formulae I, II or/and V ##STR2## in which R¹ and R² areindependently of each other C₁ -C₈ -alkyl, unsubstituted or C₁ -C₁₂-alkyl-, Cl--, Br--, I--, NO₂ -, OH--or C₁ -C₁₂ -alkoxy-substitutedphenyl or naphthyl, or benzyl, R³ is hydrogen or methyl, R⁴ and R⁵ areindependently of each other hydrogen, methyl, methoxy, --Cl or --NO₂ andR⁴ additionally in the formula I is a radical of the formula III##STR3## in which R¹⁵ and R¹⁶ are independently of each other hydrogen,C₁ -C₉ -alkyl, unsubstituted or C₁ -C₁₂ -alkyl-substituted phenyl, orbenzyl, α-methylbenzyl or α,α-dimethylbenzyl, or R¹⁵ and R¹⁶ aretogether with the C atom to which they are bonded a 5-, 6- or 7-ring,with the proviso that when R⁴ is a radical of the formula III R⁵ ishydrogen, and in which furthermore R⁶ is C₁ -C₁₈ -alkyl, C₃ -C₁₈-alkenyl, C₇ -C₁₂ -aralkyl, C₇ -C₁₂ -alkaryl or C₁ -C₁₂ -alkyl-, Cl--,Br--, I--, NO₂ --, OH--or C₁ -C₁₂ -alkoxy-ringsubstituted benzyl, R⁷ ishydrogen or methyl, R⁸, if n is 1, is hydrogen, CH₂ OR¹⁴, C₁ -C₁₈-alkyl, phenyl or --CH₂ SR¹⁴ or, if n is 2 to 4, a radical of theformulae ##STR4## and in which furthermore R⁹ is hydrogen, methyl,##STR5## or --C--R⁶, R¹⁰, R¹² and R¹³ are independently of one anotherhydrogen or methyl, R¹¹ is hydrogen, methyl or ethyl and R¹⁴ is C₁ -C₁₈-alkyl, C₇ -C₁₃ -alkaryl, phenyl, naphthyl, pentalyl, heptalyl, indacylor unsubstituted or C₁ -C₁₂ -alkyl-, Cl--, Br--, I--, NO₂ --, OH--or C₁-C₁₂ -alkoxy-ringsubstituted benzyl, n is a number from 1 to 4, m and qare numbers from 1 to 10, p is a number from 2 to 10, and R¹⁷ is eitherC_(x) H_(2x), where x is 0 to 10, or --CH═CH--.

A C₁ -C₈ -alkyl R¹ or R² is a straight-chain or branched alkyl radical,for example methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl,sec.-butyl, tert.-butyl, straight-chain or branched pentyl, hexyl,heptyl or octyl.

A C₁ -C₉ -alkyl R¹⁵ or R¹⁶ is a straight-chain or branched alkylradical, for example methyl, ethyl, n-propyl, isopropyl, n-butyl,isobutyl, sec.-butyl, tert.-butyl, straight-chain or branched pentyl,hexyl, heptyl, octyl or nonyl.

A C₁ -C₁₈ -alkyl R⁶, R⁸ or R¹⁴ is a straight-chain or branched alkylradical, for example methyl, ethyl, n-propyl, isopropyl, n-butyl,isobutyl, sec.-butyl, tert.-butyl, straight-chain or branched pentyl,hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl,tetradecyl, pentadecyl, hexadecyl, heptadecyl or octadecyl. R⁸ ispreferably C₁ -C₁₂ -alkyl.

A C₃ -C₁₈ -alkenyl R⁶ is a straight-chain or branched alkenyl radicalwhich contains one or more, but preferably one double bond, for exampleallyl, n-butenyl, 1,3-butadienyl, i-pentenyl, pentenyl, hexenyl,heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl, tridecenyl,2-nonyl-2-butenyl, tetradecenyl, pentadecenyl, hexadecenyl,8-heptadecenyl, 2-octadecenyl or oleyl. Preference is given to allyl oroleyl, in particular allyl.

In a C₁ -C₁₂ -alkyl-substituted phenyl R¹, R², R¹⁵ or R¹⁶ and a C₁ -C₁₂-alkyl-ringsubstituted benzyl R⁶ or R¹⁴, the phenyl or benzyl radicalcan be monosubstituted or polysubstituted, preferably monosubstituted ordisubstituted, in the case of and R¹⁵ R¹⁶, however, onlymonosubstituted. C₁ -C₁₂ -Alkyl is for example methyl, ethyl, n-propyl,isopropyl, n-butyl, isobutyl, sec.-butyl, tert.-butyl, straight-chain orbranched nonyl or dodecyl.

In a C₁ -C₁₂ -alkoxy-substituted phenyl R¹ or R² and a C₁ -C₁₂-alkoxy-ringsubstituted benzyl R⁶ or R¹⁴, the phenyl or benzyl radicalcan be monosubstituted or polysubstituted, but preferablymonosubstituted or disubstituted; C₁ -C₁₂ -alkoxy is, for example,methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy,sec.-butoxy, tert.-butoxy, straight-chain or branched nonyloxy ordodecyloxy.

A C₇ -C₁₂ -aralkyl R⁶, preferably phenyl-C₁ -C₄ -alkyl, is, for example,benzyl, 1- or 2-phenethyl, 3-phenyl-propyl, α, α-dimethylbenzyl,2-phenylisopropyl, 2-phenylhexyl or naphthylmethyl. Preference is givento benzyl and α,α-dimethylbenzyl, in particular benzyl.

In a C₇ -C₁₂ -alkaryl R⁶ and a C₇ -C₁₃ -alkaryl R¹⁴, the aryl radical isphenyl or naphthyl, but preferably phenyl, which are eachmonosubstituted or polysubstituted, preferably monosubstituted ordisubstituted, by C₁ -C₆ -alkyl and C₁ -C₇ -alkyl respectively,preferably by C₁ -C₄ -alkyl, e.g. 2,4,6-trimethylphenyl,2,4-dimethylphenyl, 4-isopropylphenyl, 4-hexylphenyl, 4-methylphenyl,3,4-diethylphenyl, 2-methylnaphthyl or 2,6-dimethylnaphthyl. However,preference is given to 2,5-dimethylphenyl and 4-methylphenyl, inparticular 4-methylphenyl.

Preference is given to a composition containing as component (b) atleast one compound of the formulae I or/and II in which R¹ and R² areindependently of each other C₁ -C₈ -alkyl or benzyl, particularlypreferably C₁ -C₈ -alkyl, very especially preferably C₁ -C₄ -alkyl, inparticular methyl or ethyl.

Preference is likewise given to a composition containing as component(b) at least one compound of the formulae I or/and II in which R³ ishydrogen.

Also of interest is a composition containing as component (b) at leastone compound of the formulae I or/and II in which R⁴ and R⁵ areindependently of each other hydrogen or methyl.

Of particular interest is a composition containing as component (b) atleast one compound of the formula I in which R⁴ is a radical of theformula III ##STR6##

Of similar interest is a composition containing as component (b) atleast one compound of the formula I in which R⁶ is C₁ -C₁₂ -alkyl, C₃-C₈ -alkenyl or benzyl, but preferably C₁ -C₄ -alkyl, allyl, methallylor benzyl.

Also of interest is a composition containing as component (b) at leastone compound of the formula II in which R⁷ is hydrogen.

A further embodiment is a composition containing as component (b) atleast one compound of the formula II in which R⁸ is hydrogen, C₁ -C₄-alkyl, phenyl, --CH₂ O--(CH₂)_(p) --OCH₂, --CH₂ O--(CH₂ -CH₂ --O)_(q)--CH₂ --, --(CH₂)_(m) --, ##STR7## but preferably hydrogen or methyl,and n is 1 or 2.

A specific embodiment is a composition containing as component (b) atleast one compound of the formula II in which R⁹ is hydrogen, methyl,##STR8## but preferably hydrogen.

A similarly interesting embodiment is a composition containing ascomponent (b) at least one compound of the formulae I or/and II in whichR¹³ is methyl.

A particular embodiment is a composition containing as component (b) atleast one compound of the formula II in which n is 1 or 2.

An additional embodiment is a composition containing as component (b) atleast one compound of the formula II in which m, p and q areindependently of one another a number from 2 to 6.

The present invention further provides the novel compoundsN-(2-hydroxypropyl)-2,2,4,7-tetramethyl-1,2,3,4-tetrahydroquinoline,N-[2-hydroxy-3-(tert.-nonylthio)-propyl]-2,2,4-trimethyl-1,2,3,4-tetrahydroquinoline,N-[2-hydroxy-3-(tert.-nonylthio)-propyl]-2,2,4,6-tetramethyl-1,2,3,4-tetrahydroquinoline.

The present invention likewise provides the novel compounds of theformula IV ##STR9## in which R¹ and R² are independently of each otherC₁ -C₈ -alkyl, unsubstituted or C₁ -C₁₂ -alkyl, Cl--, Br--, I--, NO₂ --,OH--or C₁ -C₁₂ -alkoxy-substituted phenyl or naphthyl, or benzyl, R³ ishydrogen or methyl, R⁶ is C₁ -C₁₈ -alkyl, C₃ C₈ -alkenyl, C₇ -C₁₂-aralkyl, C₇ -C₁₂ -alkaryl or C₁ -C₁₂ -alkyl-, Cl--, Br--, I--, NO₂ --,OH-- or C₁ -C₁₂ -alkoxy-ring-substituted benzyl, R¹³ is hydrogen ormethyl, R¹⁵ and R¹⁶ are independently of each other hydrogen, C₁ -C₉-alkyl, unsubstituted or C₁ -C₁₂ -alkyl-substituted phenyl, benzyl,α-methylbenzyl or α,α-dimethylbenzyl, or in which R¹⁵ and R¹⁶ togetherwith the C atom to which they are bonded are a 5-, 6- or 7-ring.

Specific preference is given to the compounds of the formula IV in whichR¹⁵ and R¹⁶ together with the C atom to which they are bonded are a 5-,6- or 7-ring, or R¹⁵ and R¹⁶ are independently of each other hydrogen orC₁ -C₄ -alkyl.

Examples of compounds of the formulae I and II are:1,2,2,4-tetramethyl-1,2,3,4-tetrahydroquinoline,1-ethyl-2,2,4-trimethyl-1,2,3,4-tetrahydroquinoline,1,2-dimethyl-2,4-diethyl-1,2,3,4-tetrahydroquinoline,2-methyl-1,2,4-triethyl-1,2,3,4-tetrahydroquinoline,1-benzyl-2,2,4-trimethyl-1,2,3,4-tetrahydroquinoline,1-allyl-2,2,4-trimethyl-1,2,3,4-tetrahydroquinoline,1-benzyl-2,2,4,6,7-pentamethyl-1,2,3,4-tetrahydroquinoline,1-butyl-2,2,4-trimethyl-1,2,3,4-tetrahydroquinoline,1-(2-hydroxyethyl)-2,2,4-trimethyl-1,2,3,4-tetrahydroquinoline,1-(2-hydroxypropyl)-2,2,4-trimethyl-1,2,3,4-tetrahydroquinoline,1-(2-acetoxypropyl)-2,2,4,6-tetramethyl-1,2,3,4-tetrahydroquinoline,1-(2-hydroxyethyl)-2,2,4,6-tetramethyl-1,2,3,4-tetrahydroquinoline,1-(2-hydroxyethyl)-2,4-diethyl-2-methyl-1,2,3,4-tetrahydroquinoline,1-(2-hydroxyethyl)- 2,2,4,7-tetramethyl-1,2,3,4-tetrahydroquinoline,1-(2-hydroxypropyl)-2,4-diethyl-2-methyl-1,2,3,4-tetrahydroquinoline,1-(2-acetoxyethyl)-2,2,4-trimethyl-1,2,3,4-tetrahydroquinoline,1-(β-methallyl)-2,2,4-trimethyl-1,2,3,4-tetrahydroquinoline,1,16-bis-[2,2,4-trimethyl-1,2,3,4-tetrahydroquinol-1-yl]-2,15-dihydroxy-4,13-dioxa-hexadecane,1,16-bis-[2,2,4-trimethyl-1,2,3,4-tetrahydroquinol-1-yl]-2,15-dihydroxy-4,7,10,13-tetraoxa-hexadecane,1,14-bis-[2,2,4-trimethyl-1,2,3,4-tetrahydroquinol-1-yl]-2,13-dihydroxy-4,11-dioxatetradecane,1,13-bis-[2,2,4-trimethyl-1,2,3,4-tetrahydroquinol-1-yl]-2,12-dihydroxy-4,7,10-trioxa-tridecane,1,10-bis-[2,4-diethyl-2-methyl-1,2,3,4-tetrahydroquinol-1-yl]-2,9-dihydroxy-4,7-dioxa-decane,2,2-di-{4-[3'-(2,2,4-trimethyl-1,2,3,4-tetrahydroquinol-1-yl)-2'-hydroxy-prop-1'-oxy]-phenyl}-propane,1,1-di-{4-[3'-(2,2,4,6-tetramethyl-1,2,3,4-tetrahydroquinol-1-yl)-2'-hydroxy-prop-1'-oxy]-phenyl}-methane,1-[2,2,4-trimethyl-1,2,3,4-tetrahydroquinol-1-yl)-3-(tert.-octylthio)-propan-2-ol,1-[2,2,4-trimethyl-1,2,3,4-tetrahydroquinol-1-yl)-3-(p-tolyloxy)-propan-2-ol,1-[2,2,4-trimethyl-1,2,3,4-tetrahydroquinol-1-yl)-3-(o-tolyloxy)-propan-2-ol,1-(4-butylphenyl)-2,4-diethyl-6,7-dimethoxy-2-methyl-1,2,3,4tetrahydroquinoline,1-(oleyl)-2,4-diphenyl-4-methyl-1,2,3,4-tetrahydroquinoline,1-(3-methoxy-pentadec-2-yl)-4-benzyl-6,7-dichloro-2,4-dimethyl-1,2,3,4-tetrahydroquinoline,1,1-bis[1-(3',5'-dimethyl-phenyl)-2,2,4-trimethyl-1,2,3,4-tetrahydroquinol-6-yl]-methane,1,1-bis-[1-(2'-hydroxyethyl)-2,4-diethyl-2-methyl-1,2,3,4-tetrahydroquinol-6-yl]-methane,1,1-bis-[1,2-diethyl-2,4-dimethyl-1,2,3,4-tetrahydroquinol-6-yl]cyclohexane.

The preparation of the compounds of the formulae I and II is effected ina conventional manner.

For instance, aniline and a methyl ketone can be reacted in a molarratio of 1:2 as described in Org. Synthesis, Coll. Vol. III, p. 329-32,or in U.S. Pat. No. 2,846,435. The resulting N-unsubstituted1,2,3,4-tetrahydroquinoline can be reacted in a conventional manner withcustomary alkylating, arylating or benzylating agents, e.g. dimethylsulfate, allyl bromide, iodobenzene or benzyl chloride, to the compoundsof the formula I.

The compounds of the formula II can be prepared as described in U.S.Pat. No. 3,247,211.

Novel compounds of the formula I or II can be prepared in a similarmanner.

The compounds according to the invention of the formulae I, II and IVare very highly suitable for use as antioxidants in lubricants,hydraulic oils and metal-working fluids, in particular in lubricants andhydraulic oils, especially in lubricants.

The present invention therefore also provides a method of using thecompounds of the formula I, II and IV as antioxidants in lubricants,hydraulic oils or metal-working fluids.

The compounds of the formulae I and II are sufficiently soluble inlubricants, hydraulic oils and metal-working fluids and are preferablyadded to these substrates in an amount of 0.1-2.5% by weight, based onthe total weight of the lubricant, hydraulic oil or metal-working fluidcomposition.

These lubricant, hydraulic oil or metal-working fluid systems can bepolar or apolar. The selection criteria are based on the solubilityproperties of the corresponding compounds. The lubricants, hydraulicfluids and metal-working fluids which come into consideration are knownto those skilled in the art and are described for example in"Schmiermittel Taschenbuch" (Huthig Verlag, Heidelberg, 1974), in"Ullmanns Encylopadie der technischen Chemie", volume 13, pages 85-94(Verlag Chemie, Weinheim, 1977) and D. Klamann "Schmierstoffe undverwandte Produkte" pages 158-174 (Verlag Chemie, Weinheim, 1982)respectively.

Particularly suitable are in addition to mineral oils for examplepoly-α-olefins, ester lubricants, phosphate, glycols, polyglycols andpolyalkylene glycols and mixtures thereof with water.

The lubricants, hydraulic fluids and metal-working fluids canadditionally contain other additives which are added to further improvethe basic properties of these substances; they include: furtherantioxidants, metal passivators, rust inhibitors, viscosity indeximprovers, setting point reducers, dispersants, detergents and also highpressure additives and antiwear additives.

EXAMPLES OF PHENOLIC ANTIOXIDANTS 1. Alkylated monophenols

2,6-Di-tert-butyl-4-methylphenol, 2,6-di-tert-butylphenol,2-tert-butyl-4,6-dimethylphenol, 2,6-di-tert-butyl-4-ethylphenol,2,6-di-tert-butyl-4-ethylphenol, 2,6-di-tert-butyl4-n-butylphenol,2,6-di-tert-butyl-4-iso-butylphenol, 2,6-di-cyclopentyl-4-methylphenol,2-(α-methylcyclohexyl)-4,6-dimethylphenol,2,6-di-octadecyl-4-methylphenol, 2,4,6-tricyclohexylphenol,2,6-di-tert-butyl-4-methoxymethylphenol, o-tert-butylphenol.

2. Alkylated hydroquinones

2,6-Di-tert-butyl-4-methoxyphenol, 2,5-di-tert-butyl-hydroquinone,2,5-di-tert-amyl-hydroquinone, 2,6-diphenyl-4-octadecyloxyphenol

3. Hydroxylated thiodiphenyl ethers

2,2'-Thio-bis-(6-tert-butyl-4-methylphenol),2,2'-thio-bis-(4-octylphenol),4,4'-thio-bis-(6-tert-butyl-3-methylphenol),4,4'-thio-bis-(6-tert-butyl-2-methylphenol).

4. Alkylidenebisphenols

2,2'-Methylene-bis-(6-tert-buty-4-methylphenol),2,2'-methylene-bis-(6-tert-butyl-4-ethylphenol),2,2'-methylene-bis-[4-methyl-6-(α-methylcyclohexyl)-phenol],2,2'-methylene-bis(4-methyl-6-cyclohexylphenol),2,2'-methylene-bis-(6-nonyl-4methylphenol),2,2'-methylene-bis-(4,6-di-tert-butylphenol),2,2'-ethylidene-bis-(4,6-di-tert-butylphenol),2,2'-ethylidene-bis-(6-tert-butyl-4-iso-butylphenol),2,2'-methylene-bis-[6-(α-methylbenzyl)-4-nonylphenol],2,2'-methylene-bis-[6-(α,α-dimethylbenzyl)-4-nonylphenol],4,4'-methylene-bis-(2,6-di-tert-butylphenol),4,4'-methylene-bis-(6-tert-butyl-2-methylphenol),1,1-bis-(5-tert-butyl-4-hydroxy-2-methylphenyl)butane,2,6-di-(3-tert-butyl-5-methyl-2-hydroxybenzyl)-4-methylphenol,1,1,3-tris-(5-tert-butyl-4-hydroxy-2-methyl-phenyl)-3-n-dodecylmercaptobutane,ethylene glycol bis-[3,3-bis-(3'-tert-butyl-4'-hydroxyphenyl) butyrate],di-(3-tert-butyl- 4-hydroxy-5-methylphenyl)-dicyclopentadiene,di-[2-(3'-tert-butyl-2'-hydroxy-5'-methyl-benzyl)-6-tert-butyl-4-methylphenyl]terephthalate.

5. Benzyl compounds

1,3,5-Tri-(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene,di-(3,5-di-tert-butyl-4-hydroxybenzyl) sulfide, isooctyl3,5-di-tert-butyl-4-hydroxybenzyl-mercaptoacetate,bis-(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)-dithiol terephthalate,1,3,5-tris-(3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate,1,3,5-tris-(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate,dioctadecyl 3,5-di-tert-butyl-4-hydroxy-benzyl-phosphonate, calcium saltof monoethyl 3,5-di-tert-butyl-4-hydroxybenzyl-phosphonate.

6. Acylaminophenols

4-Hydroxylauranilide, 4-hydroxystearanilide,2,4-bis-octyl-mercapto-6-(3,5-di-tert-butyl-4-hydroxyanilino)-s-triazine,octyl N-(3,5-di-tert-butyl-4-hydroxyphenyl)-carbamate.

7. Esters of β-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionic acid withmonohydric or polyhydric alcohols, for example with

    ______________________________________                                        methanol        diethylene glycol                                             octadecanol     triethylene glycol                                            1,6-hexanediol  pentaerythritol                                               neopentyl glycol                                                                              tris-hydroxyethyl isocyanurate                                thiodiethylene glycol                                                                         dihydroxyethyloxamide                                         ______________________________________                                    

8. Esters of β-(5-tert-butyl-4-hydroxy-3-methylphenyl)-propionic acidwith monohydric or polyhydric alcohols, for example with

    ______________________________________                                        methanol        diethylene glycol                                             octadecanol     triethylene glycol                                            1,6-hexanediol  pentaerythritol                                               neopentyl glycol                                                                              tris-hydroxyethyl isocyanurate                                thiodiethylene glycol                                                                         dihydroxyethyloxamide                                         ______________________________________                                    

9. Amides of β-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionic acid forexample

N,N'-di-(3,5-di-tert-butyl-4-hydroxyphenyl-propionyl)-hexamethylenediamine,N,N'-di-(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)-trimethylenediamine,N,N-di-(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)-hydrazine.

Examples of amine antioxidants

N,N'-Di-isopropyl-p-phenylenediamine,N,N'-di-sec-butyl-p-phenylenediamine,N,N'-bis(1,4-dimethyl-pentyl)-p-phenylenediamine,N,N'-bis(1-ethyl-3-methyl-pentyl)-p-phenylenediamine,N,N'-bis(1-methyl-heptyl)-p-phenylenediamine,N,N'-diphenyl-p-phenylenediamine,N,N'-di-(naphthyl-2)-p-phenylenediamine,N-isopropyl-N'-phenyl-p-phenylenediamine,N-(1,3-dimethyl-butyl)-N'-phenyl-p-phenylenediamine,N-(1-methyl-heptyl)-N'-phenyl-p-phenylenediamine,N-cyclohexyl-N'-phenyl-p-phenylenediamine,4-(p-toluene-sulfonamido)-diphenylamine,N,N'-di-methyl-N,N'-di-sec-butyl-p-phenylenediamine, diphenylamine,4-isopropoxy-diphenylamine, N-phenyl-1-naphthylamine,N-phenyl-2-naphthylamine, octylated diphenylamine, 4-n-butylaminophenol,4-butyrylamino-phenol, 4-nonanoylamino-phenol, 4-dodecanoylamino-phenol,4-octadecanoylamino-phenol, di-(4-methoxy-phenyl)-amine,2,6-di-tert-butyl-4-dimethylaminomethyl-phenol,2,4'-diamino-diphenylmethane, 4,4'-diamino-diphenylmethane,N,N,N',N'-tetramethyl-4,4'-diamino-diphenylmethane,1,2-di[(2-methyl-phenyl)-amino]-ethane, 1,2-di-(phenylamino)-propane,(o-tolyl)-biguanide, di-[4-(1',3'-dimethyl-butyl)-phenyl)amine,tert-octylated N-phenyl-1-naphthylamine, mixture of monoalkylated anddialkylated tert-butyl-/tert-octyldiphenylamines.

Examples of metal passivators are

for copper, for example:

triazole, benzotriazole and derivatives thereof,2-mercaptobenzothiazole, 2,5-dimercaptothiadiazole,salicylidenepropylenediamine, salts of salicylaminoguanidine.

Examples of rust inhibitors are

(a) organic acids, their esters, metal salts and anhydrides, forexample: N-oleoyl-sarcosine, sorbitan monooleate, lead naphthenate,dodecenylsuccinic anhydride, monoalkenyl succinates,4-nonylphenoxyacetic acid.

(b) nitrogen-containing compounds, for example: I. primary, secondary ortertiary aliphatic or cycloaliphatic amines and amine salts of organicand inorganic acids, for example oil-soluble alkylammonium carboxylates.II. heterocyclic compounds, for example: substituted imidazolines andoxazolines.

(c) Phosphorus-containing compounds, for example: amine salts of partialphosphoric esters.

(d) Sulfur-containing compounds, for example: bariumdinonylnaphthalenesulfonate, calcium petroleumsulfonates.

Examples of viscosity index improvers are for example

polymethacrylates, vinylpyrrolidone/methacrylate copolymers,polybutenes, olefin copolymers, styrene/acrylate copolymers.

Examples of setting point reducers are for example

polymethacrylate, alkylated naphthalene derivatives.

Examples of dispersants/surfactants are, for example

Polybutenylsuccinimides, polybutenylphosphonic acid derivatives, basicmagnesium, calcium and barium sulfonates and phenolates.

Examples of antiwear additives are for example Sulfur- and/orphosphorus- and/or halogen-containing compounds, such as sulfurizedvegetable oils, zinc dialkyl dithiophosphates, tritolyl phosphate,chlorinated paraffins, alkyl and aryl disulfides. EXAMPLE 1

350 g of 2,2,4-trimethyl-1,2,3,4-tetrahydroquinoline, 2000 ml of ethanoland 110 g of ethylene oxide are heated at 180° C. in an autoclave for 12hours. The ethanol is then distilled off, and the crystals of1-(2-hydroxyethyl)-2,2,4-trimethyl-1,2,3,4-tetrahydroquinoline arefiltered off. Recrystallization from ethanol gives a product having amelting point of 73°-75° C.

The method of Example 1 is repeated to prepare Examples 2-6.

EXAMPLE 7

52.6 g of 2,2,4-trimethyl-1,2,3,4-tetrahydroquinoline and 37.2 g ofdimethyl methanephosphonate are heated together for 5 hours at 160° C.in a slow stream of nitrogen. Thereafter the reaction mixture is cooleddown to 60° C. and taken up in 100 ml of toluene, and the mixture isbrought to an alkaline pH with 130 g of 10% NaOH solution. The organicphase is separated off, washed twice with 100 ml of water each time andevaporated at 80° C. in a rotary evaporator. The residue is then driedat 60° C. in a high vacuum. 54.1 g are obtained of a clear, light brownoil having a boiling point of 274° C. at 1013 mbar.

Examples 8 to 11 are obtained in a similar manner.

EXAMPLE 12

35.1 g of 1/2, 2,4-trimethyl-1,2,3,4-tetrahydroquinoline are introducedinto a flask and heated to 90° C., and 47.6 g of tert.-nonyl glycidylthioether are added dropwise with stirring. After everything has beenadded, the mixture is stirred at 90° C. for a further 0.5 hour. An oilhaving a boiling point of 185° C. at 0.03 mbar is obtained.

Example 13 is prepared in a similar manner.

                                      TABLE 1                                     __________________________________________________________________________    Example                        Melting/                                       number                                                                             Compound                  boiling point                                  __________________________________________________________________________          ##STR10##                73-75° C.                               2                                                                                   ##STR11##                110-112° C./ 0.4 mbar                   3                                                                                   ##STR12##                130-134° C./ 0.53 mbar                  4                                                                                   ##STR13##                78-79° C.                               5                                                                                   ##STR14##                120° C./ 0.2 mbar                       6                                                                                   ##STR15##                130-135° C./ 0.13 mbar                  7                                                                                   ##STR16##                274° C./ 1013 mbar                      8                                                                                   ##STR17##                84-86° C./ 0.2 mbar                     9                                                                                   ##STR18##                283° C./ 1013 mbar                      10                                                                                  ##STR19##                105° C./ 0.27 mbar                      11                                                                                  ##STR20##                296° C./ 1013 mbar                      12                                                                                  ##STR21##                185° C./ 0.03 mbar                      13                                                                                  ##STR22##                194° C./ 0.03 mbar                      __________________________________________________________________________

EXAMPLE 14 Thin-Film Oxygen Uptake Test (TFOUT)

This test is a modified version of the "rotary bomb oxidation test formineral oils" (ASTM D 2272). It is described in detail in "C. S. Ku andS. M. Hsu, A Thin-Film Oxygen Uptake Test for the Evaluation ofAutomotive Crankcase Lubricants, Lubrication Engineering, vol. 40 (2),75-83 (1984)". The test oil used is a motor oil which is based onmineral oil and contains half the customary amount of zincdithiophosphate (0.75%; zinc content 0.06%, based on the motor oil).

The compound prepared is tested in the motor oil described in thepresence of 2% of water, in the presence of a liquid oxidized nitratedfraction of a motor petrol as catalyst (4% starting concentration) andin the presence of a liquid metal naphthenate as further catalyst (4%starting concentration). The water and the two liquid catalystsubstances are supplied by the National Bureau of Standards (NBS) as No.Standard Reference Material 1817 together with a certificate ofanalysis. The test terminates with an appreciable break in thepressure/time diagram. The results indicated in Table 2 signify the time(in minutes) to the break in the pressure-time diagram.

Long times correspond to high stabilizer activity. Concentration ofstabilizer: 0.5% by weight, based on the oil.

                  TABLE 2                                                         ______________________________________                                        Stabilizer                                                                              Minutes to appreciable pressure loss                                ______________________________________                                        none       76                                                                 Example 1 199                                                                 Example 3 185                                                                 Example 4 197                                                                 Example 6 186                                                                 Example 7 220                                                                 Example 8 218                                                                 Example 9 200                                                                 ______________________________________                                    

What is claimed is: 1.N-[2-Hydroxy-3-(tert.-nonylthio)-propyl]-2,2,4-trimethyl-1,2,3,4-tetrahydroquinoline,orN-[2-hydroxy-3-(tert.-nonylthio-propyl]-2,2,4,6-tetramethyl-1,2,3,4-tetrahydroquinoline.2. A compound of the formula IV ##STR23## in which R¹ and R² areindependently of each other C₁ -C₈ -alkyl, unsubstituted or C₁ -C₁₂-alkyl or C₁ -C₁₂ -alkoxy-mono- or di-substituted phenyl or naphthyl, orbenzyl, R³ is hydrogen or methyl, R⁶ is C₁ -C₁₈ -alkyl, C₃ -C₈ -alkenyl,C₇ -C₁₂ -alkaryl or C₁ -C₁₂ -alkyl- or C₁ -C₁₂ -alkoxy-mono- or di-ring-substituted benzyl, R¹³ is hydrogen or methyl, R¹⁵ and R¹⁶ areindependently of each other hydrogen, C₁ -C₉ -alkyl, unsubstituted or C₁-C₁₂ -alkyl-substituted phenyl, benzyl, α-methylbenzyl orα,α-dimethylbenzyl.
 3. A compound according to claim 2, wherein R¹⁵ andR¹⁶ are independently of each other hydrogen or C₁ -C₄ -alkyl.